钍基氟盐冷却高温堆TRISO包覆燃料颗粒结构优化分析  

Optimization of TRISO fuel particle for thorium-based pebble bed fluoride salt-cooled high-temperature reactor

作　　者：房勇汉 蔡翔舟[1,2,3] 陈金根 胡继峰[1,2] 李晓晓 余呈刚[1,2] 伍建辉 崔德阳[1,2] FANG Yonghan;CAI Xiangzhou;CHEN Jingen;HU Jifeng;LI Xiaoxiao;YU Chenggang;WU Jianhui;CUI Deyang(Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China;Innovative Academies in TMSR Energy System, Chinese Academy of Sciences, Shanghai 201800, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]中国科学院先进核能创新研究院,上海201800 [3]中国科学院大学,北京100049

出　　处：《核技术》2019年第8期79-88,共10页Nuclear Techniques

基　　金：中国科学院战略性先导科技专项(No.XDA02010000)、中国科学院前沿科学重点研究项目(No.QYZDY-SSW-JSC016)资助~~

摘　　要：钍基氟盐冷却高温堆(Thorium-based Pebble Bed Fluoride Salt-cooled High-temperature Reactor,PBTFHR)作为第四代核反应堆的堆型之一,其燃料元件由TRISO(TRi-structural ISOtropic)包覆燃料颗粒组成,具有较好的中子性能和安全性。本工作采用 SCALE 6.1 程序开展 PB-TFHR 的临界和燃耗性能计算,结合PANAMA模型研究包覆燃料颗粒的破损率,分析了PB-TFHR中TRISO包覆燃料颗粒的kernel半径、包覆层的厚度和密度对堆芯中子学性能、裂变气体氪、氙和碘产量及包覆燃料颗粒破损率的影响,给出优化的包覆燃料颗粒结构,为其物理设计提供参考。研究发现:当保持包覆层的厚度和密度不变时,较大的kernel半径(≥0.01 cm)可使堆芯处于欠慢化区,且堆芯温度反应性系数均为负值;在相同的燃耗下,kernel半径越小,堆芯中裂变气体的生成量越少,且包覆颗粒的破损率越小;当保持包覆层密度不变,只改变包覆层的厚度时,疏松热解炭层和内致密热解炭层的厚度对keff有较大影响;而当保持包覆层厚度不变只改变包覆层的密度对keff影响较小。[Background] Thorium-based pebble bed fluoride salt-cooled high-temperature reactor (PB-TFHR) is one of the reactor types in the fourth generation reactors. It uses pebble fuel design filled with TRISO (TRi-structural ISOtropic) coated fuel particles dispersed in a graphite matrix and has good neutronic and safety performances.[Purpose] This study aims at the radius of kernel, thickness and density of coating layers of TRISO in PB-TFHR for neutron properties, the production of fission gas with krypton, xenon and iodine, and failure rate of coated fuel particles. It can provide a design reference for the reactor physics of FHR.[Methods] The Standardized Computer Analyses for Licensing Evaluation (SCALE) 6.1 program and the corresponding submodules such as burnup and cross section processing were used to calculate the critical and burnup for the PB-TFHR and the PANAMA model was used to calculate the failure rate of TRISO coated fuel particles.[Results] The results show that when the thickness and density of coating layers are maintained unchanged, a larger radius of kernel (≥0.01 cm) is required to meet the requirement that the reactor is under-moderated while the temperature feedback of core is always negative. When the thickness and density of the coating layers keep constant, at the same burnup, the smaller the radius of kernel is, the less fission gas is produced and the smaller the failure rate is. When the density of coating layers is not changed, variations of the thickness of the porous carbon buffer and the inner pyrolytic carbon layer have a great influence on the keff whilst keeping the thickness of the coating layers unchanged, only changing the density of the coating layers does not affect the keff obviously.[Conclusion] The analysis of this study give the optimal structure of TRISO coated fuel particle and provide some reference for the physical design.

关 键 词：钍基氟盐冷却高温堆 燃料球 包覆燃料颗粒 燃耗 破损率 

分 类 号：TL99[核科学技术—核技术及应用]